Hepatitis B surface antigen (HBsAG) has been shown to be effective as a vaccine against hepatitis B disease. The usual source of this antigen is plasma obtained from donors, e.g., by phasmaphoresis. As a result the supply of plasma containing this antigen is uncertain and expensive as most plasma is free of HBsAG.
It has been known heretofore to grow in vitro on hollow fiber capillary units tissue cultures of cells which shed HBsAG. The hollow fiber units used heretofore have had a molecular weight cut off of 100,000 or greater.